TALLAHASSEE — Florida’s political landscape is being upended by a landmark legal ruling that one legal expert says could influence the way other states draw their congressional districts.

A circuit judge ruled late Thursday that the state Legislature illegally drew Florida’s congressional districts to primarily benefit the Republican Party. Judge Terry Lewis ruled that two of the state’s 27 congressional districts were invalid and that the map must be redrawn.

Justin Levitt, a law professor at Loyola Law School who tracks redistricting cases, called the decision a “big victory” for Florida’s voters that could be a model for other states to follow. The judge based his decision on the 2010 “Fair Districts” amendment approved by voters that says districts cannot be drawn to favor an incumbent or a member of a political party.

“It does right by the voters who said they want a new way of doing business,” Levitt said.

But on the day after the ruling, many questions remained, including whether it could alter this fall’s elections. Florida Republicans currently hold a decisive 17-10 edge in the state’s congressional delegation even though the state has gone to President Barack Obama in the last two elections.

It appeared initially that any fallout from the decision would not develop until 2016 because the GOP-controlled Legislature would appeal the ruling. But so far, legislative leaders are being cautious about their next steps, especially since the state Supreme Court has decided against the Legislature in other recent redistricting cases.

“We just want to make sure we understand the ruling,” said House Speaker Will Weatherford on Friday.

But the coalition of groups that challenged the Legislature plans to press forward. David King, a lawyer representing the group that includes the League of Women Voters, said it would be wrong to allow the 2014 elections to go forward with illegally drawn districts.

“Our opinion is that you are not supposed to hold elections based on unconstitutional maps,” King said.

King said the groups will ask the judge next week how to comply with the decision. But state elections officials would likely oppose any effort to change districts now, since ballots for the Aug. 26 primary are about to start going out.

In the immediate aftermath of the decision, one candidate for Congress ended his campaign.

Former U.S. Rep. David Rivera, who is seeking a return to his South Florida seat despite ongoing legal issues, complained that “liberal activist judges” were holding candidates hostage because of the ruling. Rivera said he is suspending his congressional campaign and is now focused on returning to the state Legislature.

U.S. Rep. Corinne Brown, D-Jacksonville, also blasted the decision as “seriously flawed.” Brown’s sprawling district stretches from Jacksonville to Orlando and was one of the two deemed invalid by Judge Lewis. The groups suing over the districts contended the GOP-controlled Legislature packed Democrats into Brown’s seat in order to help other Republicans. But Brown maintains that the district needs to be drawn that way to ensure minority representation in Congress.

Brown’s concerns were not shared by U.S. Rep. Steve Israel.

Israel, chair of the Democratic Congressional Campaign Committee, said in a written statement, “we applaud the courts for standing up for fairness by recognizing that the congressional map is partisan and unconstitutional. We will wait to see what the judge says about a new map, but it’s a good day for Florida voters.”